Evidence needed for total knee replacements

Researchers have said there needs to be more proof that patients are happy in the long-term with total knee replacements.

The research team wrote in The Lancet that the implants, which are placed during an operation into a patient's leg to replace a damaged joint, had "proliferated" but had not been fully tested.

Although the researchers said they had not found a danger to health from the implants, they wrote that it was essential to set up "long-term monitoring" of the knee replacements.

Researcher Prof Andrew Carr, from the University of Oxford, told the BBC: "We're not sitting on a metal-on-metal situation, but there could be something not being picked up as there are not the processes going on for monitoring [total knee replacements]."

He said there were 30-40 different types of total knee replacement implants which could be bought from 15 companies.

He added that no "effectiveness or cost-effectiveness" data was usually available and that more strict regulation was required.

Dr Susanne Ludgate, clinical director of the Medicines and Healthcare Regulatory Agency, said: "The National Joint Registry (NJR) is a key source of information on the long-term safety and performance of knee joint replacements and is the largest such registry in the world."

"The NJR assists surgeons in making choices and regulators in monitoring performance. Since April 2003 all knee joint replacement operations in England and Wales have been recorded in the NJR."